Wall crack slotting grouting reinforcement and repair process based on bfrp composite reinforcing material

Abstract

The application provides a wall crack slotting grouting reinforcement repair process based on BFRP composite reinforcing bars, and belongs to the technical field of structure repair and reinforcement, and comprises the following steps: a repair slot intersecting with a wall crack is formed on the outer surface of a wall, and an anchor hole is formed on the inner wall of the repair slot; a BFRP composite reinforcing framework is assembled; the BFRP composite reinforcing framework is placed into the repair slot, and the anchor bars are anchored in the corresponding anchor holes; a sealing band is used to close the outer opening of the repair slot, the sealing band and the repair slot form a closed grouting cavity, and grout is injected into the closed grouting cavity through the pouring port. The wall crack slotting grouting reinforcement repair process based on BFRP composite reinforcing bars provided by the application forms an integral whole with the original wall and the composite reinforcing framework after the grout hardens, and can fill cracks, reinforce structures and prevent seepage, thereby improving the problem of wall crack re-cracking and water seepage.

Description

Technical Field

[0001] This application belongs to the field of structural repair and reinforcement technology, specifically involving a wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement. Background Technology

[0002] During long-term service, concrete walls are prone to developing cracks that penetrate the wall's thickness due to factors such as uneven foundation settlement, temperature shrinkage, drying shrinkage deformation, loads, and seismic forces. These cracks weaken the wall's load-bearing continuity and integrity, and create water seepage channels. Water entering the wall can accelerate the deterioration of internal materials and the expansion of cracks, posing safety hazards. Therefore, it is necessary to repair these wall cracks.

[0003] Existing surface sealing methods primarily address crack openings on the exterior of walls, making it difficult to fill internal, continuous gaps. While direct drilling and pressure grouting can fill some gaps, the cracked areas lack a continuous load-bearing framework, potentially leading to further cracking under load. The reinforcement effect of external fiber-reinforced materials is affected by the substrate treatment and interface bonding, resulting in issues such as hollow areas, peeling, and inconsistent internal and external stresses. Using ordinary steel reinforcement as a grooved reinforcement framework carries the risk of corrosion and expansion in humid environments and cement-based materials. Furthermore, pressure grouting after grooving is prone to leakage at the groove opening, and the filling status within the groove and wall is difficult to assess, affecting repair quality and construction stability. Summary of the Invention

[0004] This application provides a wall crack grooving reinforcement and repair process based on BFRP composite reinforcement, which aims to solve the problems in the existing wall through crack repair technology where there is no reliable stress connection on both sides of the crack and it is difficult to fully grout the groove and the inside of the wall.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: A wall crack grooving and grouting reinforcement repair process based on BFRP composite reinforcement is provided, including the following steps: A repair groove is made on the outer surface of the wall, intersecting with the wall crack, and anchor holes are made on the inner wall of the repair groove. Assemble a BFRP composite reinforced skeleton, wherein the BFRP is basalt fiber reinforced plastic; the BFRP composite reinforced skeleton includes longitudinal BFRP tension bars, BFRP tie bars connected to the longitudinal BFRP tension bars, and a BFRP grid covering the longitudinal BFRP tension bars and the BFRP tie bars; both ends of the longitudinal BFRP tension bars are respectively connected to outwardly extending anchor bars; The BFRP composite reinforced skeleton is placed into the repair groove, and the anchor bar is anchored into the corresponding anchor hole; The outer opening of the repair groove is sealed with a sealing strip. The sealing strip is provided with an injection port and an overflow port that communicate with the repair groove. The sealing strip and the repair groove form a closed grouting cavity. Grout is injected into the sealed grouting cavity through the injection port, and the injection port and the overflow port are sealed after the injection is completed.

[0006] In one possible implementation, the method of creating a repair groove on the outer surface of the wall that intersects with the wall crack includes: A rectangular groove is made on the outer surface of the wall, intersecting with the wall crack. The inner wall of the groove is then roughened, scum and dust are removed, it is moistened with water, and then dried until there is no standing water. Anchor holes are made between the roughening and scum and dust removal processes. The anchor holes are made on the inner wall of the treated repair groove in a direction perpendicular to the wall surface.

[0007] In one possible implementation, multiple longitudinal BFRP tension bars and multiple BFRP tie bars are provided, and the multiple longitudinal BFRP tension bars are arranged parallel to each other along the entire length of the repair groove; the BFRP tie bars include upper BFRP tie bars located above the longitudinal BFRP tension bars and lower BFRP tie bars located below the longitudinal BFRP tension bars. The upper BFRP tie bars and the lower BFRP tie bars are arranged at intervals along the longitudinal BFRP tension bars and obliquely intersect the longitudinal BFRP tension bars, and the extension directions of the upper BFRP tie bars and the lower BFRP tie bars intersect each other.

[0008] In one possible implementation, both ends of the longitudinal BFRP tension bar are covered with end BFRP fiber cloth, and the end BFRP fiber cloth is bonded to the longitudinal BFRP tension bar with epoxy resin adhesive.

[0009] In one possible implementation, the BFRP grid is a bidirectional basalt fiber mesh. The BFRP grid is tied to the straight ends of the upper and lower BFRP tie bars, and covers the longitudinal BFRP tension bars, the upper BFRP tie bars, and the lower BFRP tie bars; after the BFRP composite reinforcement skeleton is placed into the repair groove, a gap is left between the BFRP grid and the inner surface of the repair groove.

[0010] In one possible implementation, the BFRP grid has a window between two adjacent horizontal bars, the window being positioned opposite to the injection port on the sealing strip.

[0011] In one possible implementation, the anchor bar has a hook at one end facing the longitudinal BFRP tension bar, the hook hooking the end of the longitudinal BFRP tension bar, and the other end of the anchor bar is fixed in the anchor hole by anchoring adhesive.

[0012] In one possible implementation, the sealing strip is a butyl rubber waterproof sealing strip that completely covers the outer opening of the repair groove; both the injection port and the overflow port penetrate the sealing strip, and the overflow port is positioned opposite to the overflow channel on the wall.

[0013] In one possible implementation, the slurry is a PVA-ECC slurry formed by mixing engineering cement-based composite material (ECC) with water and incorporating polyvinyl alcohol (PVA) fibers.

[0014] In one possible implementation, injecting grout into the sealed grouting cavity through the injection port, and sealing the injection port and the overflow port after injection includes: The grout is injected using a grouting pump and a grouting pipe; after the grout flows out of the overflow port continuously and evenly, the grouting pipe is pulled out and the injection port and the overflow port are sealed. The wall crack grooving reinforcement and repair process based on BFRP composite reinforcement also includes: removing the sealing strip after the grout has initially set, spraying the formed grout body for curing, and then using repair mortar to smooth the outer surface of the wall corresponding to the repair groove in layers after curing.

[0015] The wall crack grooving and reinforcement repair process based on BFRP composite reinforcement provided in this application, compared with the prior art, involves opening a repair groove intersecting with the wall crack and setting anchor holes in the repair groove to anchor a composite reinforcement skeleton with longitudinal BFRP tension bars, BFRP tie bars, BFRP grids and anchor bars into the wall, so that the walls on both sides of the repair groove form a continuous stress connection, improving the integrity, tensile and shear resistance of the crack area.

[0016] BFRP material is characterized by corrosion resistance, light weight, and good durability, which can reduce the adverse effects of corrosion and expansion of traditional metal reinforcement on the repaired structure. By sealing the outer opening of the repair groove with a sealing strip and forming a closed grouting cavity using the injection port and overflow port, grout leakage during the grouting process can be reduced, and the overflow status can be used to determine whether the grout has basically filled the cavity.

[0017] After the grout hardens, it forms an integral whole with the original wall and composite reinforcement frame, thus taking into account crack filling, structural reinforcement and seepage prevention, and improving the problem of wall cracks cracking again and water seepage. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A three-dimensional structural diagram of the wall crack and repair groove provided in the embodiments of this application; Figure 2 This is a front view of the wall crack and repair groove used in the embodiments of this application; Figure 3 This is a schematic diagram of the sealing strip used in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the BFRP composite reinforcement skeleton provided in the embodiments of this application; Figure 5 This is a front view of the three-dimensional structure of the BFRP composite reinforced skeleton used in the embodiments of this application; Figure 6 This is a back view of the three-dimensional structure of the BFRP composite reinforced skeleton used in the embodiments of this application; Figure 7 This is a three-dimensional structural diagram of the bare-reinforced BFRP composite skeleton without covered grid used in the embodiments of this application; Figure 8 This is a side perspective view of a BFRP grille with an open window provided in an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 1. Wall; 11. Wall cracks; 12. Repair groove; 13. Anchor hole; 14. Grout overflow channel; 2. BFRP composite reinforced skeleton; 21. Longitudinal BFRP tension bar; 22. BFRP tie bar; 221. Upper BFRP tie bar; 222. Lower BFRP tie bar; 23. BFRP grid; 231. First transverse grid bar; 232. Second transverse grid bar; 24. End BFRP fiber cloth; 3. Anchor bars; 4. Sealing strip; 41. Injection port; 42. Overflow port. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is actually illustrative only and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0024] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Additionally, "multiple" and "several" mean two or more, unless otherwise explicitly specified.

[0026] Please refer to the following: Figures 1 to 8This application describes the wall crack grooving and reinforcement repair process based on BFRP composite reinforcement. The wall crack grooving and reinforcement repair process based on BFRP composite reinforcement includes the following steps: creating a repair groove 12 intersecting with the crack on the outer surface of the wall 1, and creating anchor holes 13 on the inner wall of the repair groove 12; assembling a BFRP composite reinforcement skeleton 2, where BFRP is basalt fiber reinforced plastic; the BFRP composite reinforcement skeleton 2 includes longitudinal BFRP tension bars 21, BFRP tie bars 22 connected to the longitudinal BFRP tension bars 21, and BFRP reinforcement covering the longitudinal BFRP tension bars 21 and the BFRP tie bars 22. RP grid 23; the two ends of the longitudinal BFRP tension bar 21 are respectively connected to outwardly extending anchor bars 3; the BFRP composite reinforced skeleton 2 is placed into the repair groove 12, and the anchor bars 3 are anchored in the corresponding anchor holes 13; the outer opening of the repair groove 12 is sealed with a sealing strip 4, and the sealing strip 4 is provided with an injection port 41 and an overflow port 42 communicating with the repair groove 12. The sealing strip 4 and the repair groove 12 form a closed grouting cavity; grout is injected into the closed grouting cavity through the injection port 41, and the injection port 41 and the overflow port 42 are sealed after the injection is completed.

[0027] It should be noted that a through crack refers to a crack that runs through or nearly runs through the thickness of the wall 1. During implementation, the continuity of the crack is first confirmed with a crack observation instrument, then cross repair grooves 12 are opened on both sides of the crack, reinforcement and mesh are arranged, and after the sealant is pasted, pressure grouting is performed.

[0028] It should be noted that BFRP composite reinforcement refers to non-metallic reinforcement materials that use basalt fiber as the main reinforcing phase, resin as the matrix, and are formed by pultrusion or braiding. BFRP is an abbreviation for Basalt Fiber Reinforced Polymer, referring to basalt fiber reinforced plastics formed by using basalt fiber as the reinforcing material and resin as the matrix. The specific forms of longitudinal BFRP tension bars 21, BFRP tie bars 22, and BFRP grids 23 are different, but they all belong to basalt fiber composite materials.

[0029] It should be noted that the repair groove 12 refers to a strip-shaped groove opened along the through crack in the wall surface and intersecting the crack, used to accommodate reinforcing materials and mesh. Intersecting means that the extended area of ​​the repair groove 12 crosses the crack in the wall 1, allowing the crack in the wall 1 to enter or pass through the repair groove 12, without requiring the repair groove 12 to be strictly perpendicular to the crack. Preferably, in the embodiment, the repair groove 12 is 80mm wide and 35mm deep, and the bottom of the groove crosses the center line of the crack and remains continuous.

[0030] It should be noted that "longitudinal" refers to the reinforcement material being installed along the entire length of the repair groove 12, relative to the repair groove 12. The longitudinal BFRP tension reinforcement 21 is used to cross the cracks in the wall 1 and bear the main tensile force generated by the crack opening.

[0031] It should be noted that the anchoring hole refers to the hole drilled from the bottom of the repair groove 12 into the intact wall 1 for installing the anchoring bar 3. Preferably, in the embodiment, the hole diameter is 14mm and the hole depth is 120mm, the hole axis is perpendicular to the wall surface, and the hole is cleaned with compressed air and a brush after drilling.

[0032] It should be noted that BFRP grid 23 refers to a mesh reinforcement formed by weaving continuous BFRP fiber bundles in two intersecting directions. Preferably, the embodiment uses a two-way mesh with 25mm apertures and a 50mm straight overlap section reserved at the ends.

[0033] The wall 1 crack grooving reinforcement and repair process based on BFRP composite reinforcement provided in this embodiment, compared with the prior art, organizes the treatment of through cracks in wall 1, repair groove 12, anchor holes, BFRP composite reinforcement skeleton, sealing grouting cavity and pressure grouting steps into a continuous process, so that the cavity filling inside the crack, the load transfer on both sides of the crack and the wall protection are completed in the same construction system.

[0034] The repair groove 12 provides synergistic constraints on the crack in both the transverse and longitudinal directions. The BFRP tension bars and BFRP grid 23 form a multi-directional force path, which can disperse the concentrated deformation at the crack tip to a larger area of ​​the wall 1. The anchor bars 3 transfer the tensile force of the BFRP composite reinforced skeleton 2 to the intact wall 1, avoiding reliance solely on surface bonding.

[0035] The longitudinal BFRP tie bars 21, BFRP reinforcing bars 22, and BFRP grid 23 together form a multi-directional constraint, which can limit the opening, displacement, and propagation of cracks along the wall surface. The sealing strip 4 seals the repair groove 12 into a controllable cavity. Under pressure, the grout enters the crack and the gaps around the BFRP composite reinforced skeleton 2. After curing, it connects the original wall 1, the BFRP composite reinforced skeleton 2, and the grout into a whole.

[0036] After the sealing element forms a closed grouting cavity, the grout can penetrate deep into the cracks and fine pores under controlled pressure. The degree of filling can be judged by the grout discharge status, thereby reducing the risk of grout leakage, under-grouting, and internal voids. The cured grout forms a composite whole with the original wall 1 and BFRP skeleton, taking into account crack resistance, durability, and waterproof performance. It is suitable for repairing wall 1 in environments with large temperature and humidity changes, with through cracks, and where large-area demolition is not advisable.

[0037] In some embodiments, opening a repair groove 12 intersecting with the crack in the wall 1 on the outer surface of the wall 1 includes: opening a rectangular groove intersecting with the crack in the wall 1 on the outer surface of the wall 1; sequentially roughening the inner wall of the groove, removing scum and dust, wetting it with clean water, and drying it until there is no standing water; between roughening and removing scum and dust, opening anchor holes 13, the anchor holes 13 being opened on the inner wall of the treated repair groove 12 in a direction perpendicular to the wall surface.

[0038] It should be noted that roughening is to remove the laitance from the groove wall and create a rough surface; "anchor holes perpendicular to the wall surface" allows for construction deviations but should ensure the effective anchor length.

[0039] In practice, a 14mm drill bit is used to drill a 120mm hole, and after cleaning the hole, epoxy anchoring adhesive is applied in a saturated, surface-dry state.

[0040] In this embodiment, by roughening the inner wall of the repair groove 12, cleaning the floating dust, and wetting it with clean water until it is saturated and dry, the loose layer can be removed, mechanical interlocking can be increased, and the excessive water absorption of the base layer can be avoided, which would cause the adhesive to lose water too quickly. The anchoring holes are directional drilled and the hole axis is basically perpendicular to the wall surface, which can effectively embed the anchoring bar 3 into the complete wall 1, reducing the eccentric force and local splitting caused by the inclined hole.

[0041] This embodiment provides a clean, rough, and humidity-controlled bonding interface for epoxy anchoring adhesive, enabling the adhesive to fully wrap the anchor bar 3 and form a continuous bonding layer on the hole wall.

[0042] Roughening the surface increases the roughness of the groove wall and the effective bonding area. Sweeping away loose dust can prevent loose particles from becoming the interface slip surface. Wetting with clean water and then blowing away the free water on the surface can make the base layer suitable for the construction of anchoring adhesive and grouting materials, and reduce local shrinkage caused by water absorption by the base layer.

[0043] The anchor holes are oriented in a uniform direction and distributed on the inner wall of the groove, which can keep the effective length and force direction of the anchor bar 3 stable and reduce eccentricity, hole splitting and skeleton installation deviation caused by inclined holes.

[0044] Compared to simply applying sealing material to the crack surface, this embodiment incorporates interface quality, hole position accuracy, and anchoring reliability into the same quality control process. This can stabilize the positioning of the subsequent BFRP skeleton, improve the shear force transmission between the repair layer and the original wall 1, and reduce the probability of debonding, loosening, and secondary cracking after long-term wet and dry cycles.

[0045] In some embodiments, see Figures 4 to 7 Multiple longitudinal BFRP tension bars 21 and BFRP tie bars 22 are provided. The multiple longitudinal BFRP tension bars 21 are arranged parallel to each other along the entire length of the repair groove 12. The BFRP tie bars 22 include an upper BFRP tie bar 221 located above the longitudinal BFRP tension bars 21 and a lower BFRP tie bar 222 located below the longitudinal BFRP tension bars 21. The upper BFRP tie bars 221 and the lower BFRP tie bars 222 are arranged at intervals along the longitudinal BFRP tension bars 21 and are oblique to the longitudinal BFRP tension bars 21. The extension directions of the upper BFRP tie bars 221 and the lower BFRP tie bars 222 intersect each other.

[0046] In this embodiment, the longitudinal BFRP tension bars 21 are arranged in parallel through the repair groove 12. The upper BFRP tie bars 221 and the lower BFRP tie bars 222 are interlaced with the BFRP grid 23, and the upper BFRP tie bars 221 and the lower BFRP tie bars 222 are parallel to each other, and the BFRP grid 23 intersects with them to form a spatial force network.

[0047] This arrangement distributes the tensile stress, shear stress, and temperature shrinkage stress on both sides of the crack to the composite reinforcement in different directions, avoiding excessive local strain in the BFRP reinforcement in a single direction when the crack opens.

[0048] The staggered arrangement can also form continuous overlaps and constraint nodes, so that after the grout solidifies, a stable anchoring zone is formed around the reinforcement. When the wall 1 is repeatedly opened and closed or sheared in the plane, the upper BFRP tie bar 221 and the lower BFRP tie bar 222 can work together, while the BFRP grid 23 restricts the crack from continuing to extend along the wall surface.

[0049] All reinforcing materials are located within the grooved area, with minimal exposed height, facilitating subsequent sealing and finishing, and reducing the impact on the original wall surface flatness. This geometric relationship can improve the tensile, shear, and peel strength of cracked areas without significantly increasing the wall thickness.

[0050] In some embodiments, see Figure 5 and Figure 6 Both ends of the longitudinal BFRP tension rib 21 are covered with end BFRP fiber cloth 24, and the end BFRP fiber cloth 24 and the longitudinal BFRP tension rib 21 are bonded together with epoxy resin adhesive.

[0051] It should be noted that the end BFRP fiber cloth 24 is a continuous fiber cloth used to extend the force transmission path.

[0052] In this embodiment, resin bonding is provided between the longitudinal BFRP reinforcement and the end BFRP fiber cloth 24, so that a reliable mechanical transition is formed between the longitudinal BFRP reinforcement and the end BFRP fiber cloth 24. The end BFRP fiber cloth 24 can gradually diffuse the axial tensile force of the longitudinal BFRP tension reinforcement 21 to the grout and the wall 1, reducing stress concentration at the abrupt termination of the reinforcement; after the epoxy resin cures, it can also seal the micropores between the end BFRP fiber cloths 24, inhibiting voids and local slippage caused by grout penetration.

[0053] The BFRP materials are bonded together with resin, eliminating the need for welding or high-temperature treatment, thus avoiding heat damage and corrosion of metal connectors in humid environments. The end connections also allow for easy adjustment of the overlap range based on the length of the repair groove 12, ensuring that the effective anchorage length of the BFRP is not limited by the standard component length.

[0054] After curing, the end BFRP fiber cloth 24, epoxy resin, grouting material and anchor bar 3 form a continuous force flow conversion zone, which can improve the pull-out and peel resistance of the skeleton end and reduce the risk of the repair layer gradually detaching from the groove end.

[0055] This connection method does not rely on metal welding or mechanical sleeves, avoiding heat damage to BFRP and corrosion at the interface of dissimilar materials. The fiber cloth can be cut according to the length of the repair groove 12 to adapt to on-site dimensional deviations.

[0056] Specifically, during construction, the surface of the reinforcing material is first dusted and coated with two-component epoxy resin. Then, the end fiber cloth is wrapped or pressed with a specified overlap length. Position adjustment can be completed before curing, and after curing, a flexible but high-strength anchoring end is formed.

[0057] In this embodiment, the load caused by the opening and closing of cracks can be smoothly transferred between the reinforcement material, resin, grout and wall 1, which can improve the integrity and fatigue durability of the reinforced frame.

[0058] In some embodiments, see Figure 5 and Figure 6 The BFRP grid 23 is a bidirectional basalt fiber mesh. The BFRP grid 23 is tied to the straight ends of the upper BFRP tie bar 221 and the lower BFRP tie bar 222, and covers the longitudinal BFRP tension bar 21, the upper BFRP tie bar 221 and the lower BFRP tie bar 222. After the BFRP composite reinforced skeleton 2 is placed into the repair groove 12, a gap is left between the BFRP grid 23 and the inner surface of the repair groove 12.

[0059] In this embodiment, a fiber mesh is used as the BFRP grid 23, with its straight ends respectively attached to the ends of the upper BFRP tie bars 221 and the lower BFRP tie bars 222, while leaving a gap between the mesh and the inner wall of the repair groove 12. The bidirectional mesh forms a planar constraint within the wall surface, which can suppress local peeling, diagonal expansion, and end splitting of cracks on both sides; after the mesh ends overlap with the upper and lower layers of reinforcement, the in-plane tensile force can be transferred to the strip reinforcement and anchor bars 3, improving the synergy between point anchoring and planar reinforcement.

[0060] The spacing between the mesh and the trench wall provides a channel for the grout coating, preventing the mesh from adhering too closely to the substrate and forming an unfilled interlayer. This ensures that the curing material continuously wraps around both sides of the mesh and plays a bonding role. The bidirectional continuous fiber arrangement also enables the reinforcement layer to more uniformly disperse temperature deformation and shrinkage deformation, reducing local cracks caused by excessive spacing between unidirectional reinforcing bars.

[0061] Specifically, this embodiment can use prefabricated mesh sheets placed on-site, which allows for quick construction positioning and minimal disturbance to the wall surface, making it suitable for the overall repair of long cracks and areas where multiple cracks intersect.

[0062] In some embodiments, see Figure 5 The BFRP grid 23 has a window between two adjacent horizontal bars, and the window is positioned opposite to the injection port 41 on the sealing strip 4.

[0063] Specifically, these two adjacent horizontal bars are defined as the first horizontal bar 231 and the second horizontal bar 232.

[0064] In this embodiment, a reserved opening is set between the BFRP grid 23 and the mesh, and grout is injected into the sealant through the opening. The reserved opening provides a continuous flow section for the grout, allowing the grout to bypass the mesh nodes and diffuse into the depth of the crack, avoiding stagnation, air pockets, or dry spots in dense mesh areas; the opening also acts as a buffer and grout storage function, absorbing flow changes when the grouting pressure fluctuates for a short time, reducing local bulging of the sealing strip 4.

[0065] The size of the opening can be adjusted according to the crack length, mesh aperture and grout flowability, so as to ensure the filling speed without reducing the coating thickness of the mesh and reinforcement.

[0066] During grouting, operators can observe whether the grout flows continuously through adjacent outlets to determine the connectivity of voids and cracks. Sealing the pipes only after the grout flow is uniform and free of obvious air bubbles reduces the risk of hidden internal voids and under-grouting. After curing, the voids are filled with grout, forming a core with a certain degree of toughness, further improving the crack resistance and waterproofing of the repair layer.

[0067] In some embodiments, the anchor bar 3 is provided with a hook at one end facing the longitudinal BFRP tension bar 21, the hook hooks the end of the longitudinal BFRP tension bar 21, and the other end of the anchor bar 3 is fixed in the anchor hole 13 by anchoring adhesive.

[0068] In this embodiment, the hook enables the anchor bar 3 to form mechanical engagement and direction conversion in the anchor hole 13 and the repair groove 12 respectively, increasing the pull-out path and restricting the anchor bar 3 from sliding along the hole axis; after being connected to the end of the longitudinal BFRP tension bar 21, the tensile force generated by the crack opening can be transmitted from the longitudinal BFRP tension bar 21 to the anchor bar 3, and then transmitted to the complete wall 1.

[0069] Wrapping the anchor bars 3 with adhesive and filling irregular areas of the hole wall improves the bonding continuity within the hole and reduces moisture seepage along the duct. This embodiment also allows for the adaptation of anchor bars 3 with different diameters by controlling the bending angle and radius, avoiding localized damage caused by excessive bending at the ends. A clear and inspectable anchoring node is formed between the BFRP skeleton and the wall 1, reducing the possibility of pull-out, slippage, or end cracking of the repair layer under repeated loads.

[0070] In some embodiments, see Figure 3The sealing strip 4 is a butyl rubber waterproof sealing strip 4, which completely covers the outer opening of the repair groove 12; the injection port 41 and the overflow port 42 both penetrate the sealing strip 4, and the overflow port 42 is set opposite to the overflow channel 14 on the wall 1.

[0071] In this embodiment, the sealing strip 4 is made of butyl rubber waterproof sealing material, and both the grouting port and the grout outlet penetrate the sealing element and are connected to the repair groove 12.

[0072] The viscoelasticity of butyl rubber allows the sealing strip 4 to conform to the slight unevenness of the groove and maintain continuous water stop when the wall 1 deforms; The through-hole grouting port provides a stable grout inlet channel, while the outlet serves as a vent, overflow, and replenishment port, allowing air within the sealed cavity to be replaced and the degree of filling to be determined by the grout condition. Placing the outlet at the end or high position of the cavity reduces under-filling caused by air resistance; sealing both openings after grouting maintains the sealed environment required for grout solidification.

[0073] This embodiment combines waterproofing, drainage, and construction to avoid the problem that traditional methods rely solely on surface sealing and cannot identify internal grout leakage. It also facilitates prefabrication, cutting, and rapid on-site installation.

[0074] Specifically, the sealing strip 4 is made of bonded butyl rubber waterproof sheet, which is continuously pressed and bonded around the periphery of the repair groove 12; grouting port and grout outlet are opened on the sealing sheet so that the two penetrate the sealing sheet and communicate with the space inside the groove, and an airtightness test is performed after bonding.

[0075] In some embodiments, the slurry is a PVA-ECC slurry formed by mixing engineering cement-based composite material (ECC) with water and incorporating polyvinyl alcohol (PVA) fibers.

[0076] Specifically, PVA-ECC grout refers to a pumpable grout that uses cement-based ECC as the cementitious matrix, water as the mixing medium, and incorporates polyvinyl alcohol fibers.

[0077] Specifically, the slurry is prepared using cement-based ECC dry material and water, with a water-cement ratio of 20%. PVA fibers with a volumetric admixture of 1.5% and a length of 8mm are added, and the mixture is stirred in stages until the fibers are evenly dispersed. The actual mix proportions are adjusted based on pumping performance and the width of cracks in the wall.

[0078] In this embodiment, cement-based ECC provides a pumpable continuous matrix that can enter through cracks, repair grooves 12, and small gaps around reinforcement under pressure; PVA fibers form bridging after hardening, limiting the penetration of matrix shrinkage cracks and cracks caused by wall deformation, thus giving the filling material good tensile deformation capacity.

[0079] Compared with ordinary brittle cement grout, PVA-ECC is less prone to forming through cracks under repeated crack opening and closing, temperature changes and wet-dry cycles, and can continuously coat BFRP reinforcement and maintain adhesion. Compared with simple resin grouting, its material composition has better compatibility with cement-based walls, and has higher fire resistance and adaptability to large-volume filling.

[0080] By controlling the water-cement ratio, fiber length, and dispersion uniformity, a balance can be achieved between pumpability, strength, and toughness, providing a continuous and durable encapsulation and force transmission medium for the BFRP skeleton.

[0081] In some embodiments, injecting grout into a closed grouting cavity through the injection port 41 and sealing the injection port 41 and the overflow port 42 after injection includes: injecting grout using a grouting pump and a grouting pipe; after the grout flows out of the overflow port 42 continuously and evenly, pulling out the grouting pipe and sealing the injection port 41 and the overflow port 42; the wall 1 crack grooving reinforcement and repair process based on BFRP composite reinforcement also includes: removing the sealing strip 4 after the grout has initially set, spraying the formed grout body for curing, and after curing, using repair mortar to smooth the outer surface of the wall 1 corresponding to the repair groove 12 in layers.

[0082] In this embodiment, grout is injected into the sealed cavity through the grouting port. After the grout overflows from the grout outlet, the grouting pipe is pulled out and the grouting port is sealed. Grout is then added again from the grout outlet. After the grout hardens, the sealing parts are removed and the repair groove 12 is smoothed with non-shrink mortar.

[0083] The process of injecting first and then overflowing grout can expel air from the cavity and confirm the continuity of the grouting channel. After the pipe is pulled out and sealed, replenishing grout from the outlet can make up for local under-grouting at the end of the cavity or around the grid. Arranging the sealing and replenishing to be completed while the grout is still fluid can reduce the damage to the sealing structure caused by secondary opening; waiting for the grout to harden before finishing can avoid premature covering that would prevent internal defects from being detected.

[0084] The non-shrink mortar is used to fill the grooves in layers and restore the flatness of the wall surface. This creates a clear sequence between structural reinforcement, waterproofing, and appearance repair, forming a construction closed loop that is easy to record and accept. At the same time, it reduces the impact of uncontrolled grouting pressure, grout leakage, and shrinkage hollowing on long-term durability.

[0085] The following are several embodiments of this application: Example 1: Please see Figures 1 to 8 This embodiment provides a wall crack grooving reinforcement and repair process based on BFRP composite reinforcement material, which is used to repair through wall cracks 11 on concrete wall 1.

[0086] In this embodiment, BFRP refers to basalt fiber reinforced plastic, and the structures in the BFRP composite reinforced skeleton 2 are all made of basalt fiber composite material.

[0087] Before construction, inspect the extension direction, length, width, penetration of the wall crack 11, and the integrity of the walls on both sides of the crack. Determine the location of the repair groove 12, avoiding existing reinforcing bars, pipelines, and embedded parts within the wall. The repair groove 12 intersects with the wall crack 11, meaning it spans across the crack, allowing the framework to connect the walls on both sides of the crack, without requiring them to be strictly perpendicular. For example, when the wall crack 11 extends approximately vertically, the repair groove 12 is set horizontally, with the wall crack 11 passing through the middle of the repair groove 12.

[0088] A rectangular boundary is cut on the outer surface of wall 1 using a handheld concrete cutting device, and then the concrete within the boundary is removed to form a rectangular repair groove 12. The repair groove 12 can be set to a length of about 600mm and a width of about 150mm according to the range of the crack and the size of the skeleton. The groove depth is determined according to the ability to accommodate the BFRP composite reinforced skeleton 2, the grout protective layer and the allowable construction deviation.

[0089] After the repair groove 12 is formed, its bottom and sidewalls are roughened to remove the loose cement slurry skin and create a rough interface. Anchor holes 13 are then drilled into the inner wall of the repair groove 12. The anchor holes 13 extend into the wall perpendicular to the wall surface and are respectively located on the relatively intact wall areas on both sides of the wall crack 11. The diameter and depth of the anchor holes 13 are determined based on the diameter of the anchor bar 3, the performance of the anchoring adhesive, and the designed anchoring force.

[0090] After the anchor holes 13 are constructed, use a brush and a high-pressure blower to remove scum and dust from the repair groove 12 and anchor holes 13. Repeat brushing and blowing as needed to prevent residual dust on the hole walls from reducing the bonding strength of the anchoring adhesive. After cleaning, evenly moisten the inner surface of the repair groove 12 with clean water and allow it to air dry until there is no visible water. No visible water means that the groove walls remain moist but there is no observable continuous water film, water droplets, or standing water. This reduces the rate at which the old concrete absorbs the mixing water from the grout and prevents free water films from weakening the interfacial bond between the old and new materials.

[0091] Prefabricate the BFRP composite reinforcement frame 2 off-site. First, arrange three ribbed longitudinal BFRP tension bars 21 with a diameter of 10mm parallel to each other along the length of the repair groove 12, with a clear distance of 50mm between adjacent longitudinal BFRP tension bars 21. The length of the repair groove 12 refers to the length direction of the rectangular repair groove 12 extending from one end to the other. After installation, the longitudinal BFRP tension bars 21 span the wall crack 11 and are used to bear the main tensile force generated by the crack opening trend.

[0092] Multiple upper BFRP tie bars 221 are provided on the upper side of the longitudinal BFRP tension bar 21, and multiple lower BFRP tie bars 222 are provided on the lower side of the tension bar 21. The upper BFRP tie bars 221 and the lower BFRP tie bars 222 together constitute the BFRP tie bar 22. Both the upper BFRP tie bars 221 and the lower BFRP tie bars 222 can be made of ribbed BFRP bars with a diameter of 8mm, and a set is provided every 100mm along the longitudinal BFRP tension bar 21. The upper BFRP tie bars 221 form an angle of approximately 45° with the longitudinal BFRP tension bar 21, and the lower BFRP tie bars 222 are placed diagonally in the opposite direction, so that the projected extension directions of the upper BFRP tie bars 221 and the lower BFRP tie bars 222 intersect each other. This cross arrangement connects multiple longitudinal BFRP tension bars 21 into a whole, and can convert the relative misalignment on both sides of the wall crack 11 into axial force of the tension bars, thereby improving the shear resistance of the crack area.

[0093] The upper BFRP tie bar 221 and the lower BFRP tie bar 222 can be provided with 90° bent connections or adopt a binding connection structure adapted to the longitudinal BFRP tension bar 21. The tie bar retains a straight end section near the outer perimeter of the skeleton. The straight end section refers to the straight part that is not bent and can be used to fix the BFRP grid 23.

[0094] Both ends of each longitudinal BFRP tension bar 21 are covered with end-piece BFRP fiber cloth 24. During construction, the ends of the longitudinal BFRP tension bars 21 are first cleaned, then epoxy resin is applied, and the end-piece BFRP fiber cloth 24 is wrapped around the ends of the longitudinal BFRP tension bars 21 and compacted. After the epoxy resin cures, an end-reinforced area is formed. The end-piece BFRP fiber cloth 24 can increase the interaction area between the ends of the longitudinal BFRP tension bars 21 and the grout, diffuse the concentrated stress at the ends to the surrounding grout, and reduce the risk of BFRP grid 23 pull-out and end grout splitting.

[0095] Anchor bars 3 extending outwards are provided at both ends of the BFRP composite reinforced skeleton 2. "Extending outwards" means that the anchor bars 3 extend outwards from the ends of the skeleton along its length, not that they protrude beyond the wall surface. The anchor bars 3 can be made of 10mm diameter HRB400 steel bars, with a 135° hook at one end facing the longitudinal BFRP tension bar 21. The hook connects to the end of the longitudinal BFRP tension bar 21; the other end of the anchor bar 3 serves as the anchoring section for insertion into the anchor hole 13. The hook connection avoids welding or drilling of the BFRP bars, establishing a mechanical force transmission path while minimizing local damage to the BFRP bars.

[0096] A BFRP (Bio-Fiber Reinforced Plastic) grid 23 is used to cover the longitudinal BFRP tension bars 21, as well as the upper and lower BFRP tie bars 221 and 222. The BFRP grid 23 is a bidirectional basalt fiber mesh with a mesh size of up to 25 mm. The BFRP grid 23 is tied to the straight ends of the upper and lower BFRP tie bars 221 and 222, keeping the grid in an unfolded state and forming a stable cage structure with the internal reinforcement. The mesh openings of the grid allow grout to pass through, allowing the grout inside and outside the grid to bond together after hardening.

[0097] At a position corresponding to the subsequent injection port 41, a window is provided between the first horizontal bar 231 and the second horizontal bar 232 of the BFRP grid 23. The distance between the first horizontal bar 231 and the second horizontal bar 232 is 75mm, and the size of the resulting window is 75mm × 50mm. The window is an open area larger than the original mesh opening, formed after partially removing the grid bars. This window provides a direct passage for the grouting pipe and the PVA fiber-containing grout, preventing the grouting pipe from contacting the horizontal bars and reducing fiber bridging and blockage at the inlet.

[0098] After the skeleton is prefabricated, the anchor holes 13 are cleaned again, and epoxy resin anchoring adhesive is injected from the bottom of the hole to the opening. The BFRP composite reinforced skeleton 2 is placed into the repair groove 12 as a whole, and the anchoring sections of the anchor bars 3 at both ends are rotated and inserted into the corresponding anchor holes 13, so that the anchoring adhesive evenly fills the gap between the anchor bars 3 and the hole wall. The position of the skeleton is adjusted so that the longitudinal BFRP tension bars 21 cross the wall crack 11, and a gap is left between each outer surface of the BFRP grid 23 and the inner surface of the repair groove 12. This gap is 5mm. This gap is used to ensure that the grout can enter the outside of the grid and form a continuous protective layer, avoiding the BFRP grid 23 directly contacting the old concrete and creating an interface that is not filled by the grout.

[0099] Prepare the PVA-ECC grout. Mix the dry ECC material with water, where the water volume is 20% of the dry ECC material's mass. Add 8mm long PVA fibers, accounting for 1.5% of the total mass. First, mix the ECC material with water until it reaches a uniform, fluid state, then gradually disperse the PVA fibers to avoid clumping caused by a single, concentrated addition of fibers. Before formal grouting, test the grout's fluidity, uniformity, and pumpability. If the recommended water volume for the ECC product used differs from the example above, the test results that meet the design strength, bonding performance, and pumpability shall prevail.

[0100] After the adhesive has reached a condition suitable for subsequent construction, cover the entire outer opening of the repair groove 12 with butyl rubber waterproof sealing tape 4. As a specific example, the sealing tape 4 is 5mm thick, 700mm long, and 200mm wide, its dimensions being larger than the groove opening of the repair groove 12, thus forming a continuous adhesive edge around the groove opening. Before application, remove dust, oil, and loose materials from the wall surface around the groove opening. Then, press the sealing tape 4 from one end to the other, focusing on compacting it around the groove opening to avoid wrinkles and air passages.

[0101] An injection port 41 and an overflow port 42 are provided on the sealing strip 4. The injection port 41 is opposite to the window on the BFRP grid 23, and the injection port 41 can be a circular hole with a diameter of 42mm. The overflow port 42 can be a square hole with a side length of 10mm, and is located at a relatively high and far position to the upper right of the injection port 41 or in the cavity. An overflow channel communicating with the repair groove 12 is pre-set on the wall 1, and the overflow port 42 on the sealing strip 4 is opposite to this overflow channel. "The overflow channel built into the wall" refers to the channel that has been set or formed on the wall before the sealing strip 4 is pasted, and is not a naturally existing hole in the original wall.

[0102] The sealing strip 4 and the repair groove 12 together form a sealed grouting cavity. The term "sealed" here is relative to the grouting process. That is, except for the injection port 41, the overflow port 42 and the wall crack 11 connected to the repair groove 12, the outer opening of the repair groove 12 is continuously sealed by the sealing strip 4. This does not mean that the cavity is absolutely airtight or in a vacuum state.

[0103] Grouting is performed using a miniature grouting pump capable of delivering fiber-containing grout and a DN32 grouting pipe. The grouting pipe is inserted into the injection port 41 and aligned with the opening of the BFRP grid 23. PVA-ECC grout is injected into the sealed grouting cavity at a sample flow rate of approximately 5 L / min. The actual grouting flow rate and pressure are adjusted based on the grout fluidity, tank volume, wall strength, and the pressure-bearing state of the sealing strip 4 to avoid excessive grouting pressure that could cause the sealing strip 4 to lift at the edges or cause localized damage to the original wall.

[0104] After the grout enters the skeleton through the injection port 41, it flows through the mesh holes of the BFRP grid 23 to the outer perimeter of the skeleton, both ends of the repair groove 12, and the wall cracks 11. As the grout is continuously injected, air in the cavity is discharged through the overflow port 42. When the overflow port 42 changes from venting and intermittent dripping to a continuous flow of grout with a relatively stable flow rate and without obvious air bubbles, and the grout has an appearance that is basically the same as the injected grout, it can be determined that the main cavity between the injection port 41 and the overflow port 42 is basically filled.

[0105] Once the above conditions are achieved, stop grouting and slowly pull out the grouting pipe. Immediately use butyl rubber sealing material to seal the injection port 41 and overflow port 42 respectively to prevent the grout that has not yet set from flowing back. Leave the sealing strip 4 covering the repair trench 12 in place until the grout sets. Initial setting refers to the stage when the grout begins to lose its plasticity and is able to maintain the shape of the trench opening. The specific time is determined based on the material properties and the site temperature.

[0106] After the grout has initially set, remove sealing strip 4 and inspect the surface of the grouting body. If localized shallow grout gaps are found, they can be filled with similar repair materials without damaging the main grouting body. Subsequently, spray the grouting body to keep the surface moist for at least 7 days, or follow the product requirements and design specifications of the ECC material used. Avoid using concentrated water jets to directly wash the grouting body before it has reached sufficient strength.

[0107] After curing is completed and the grouting material meets the requirements, the outer surface of the wall corresponding to the repair groove 12 is smoothed in layers using repair mortar compatible with the original wall. First, the patching layer is applied and compacted. After it reaches the allowable construction state, the surface layer is applied. Finally, it is sanded smooth to ensure a smooth transition between the repaired area and the surrounding wall surface.

[0108] In this embodiment, the longitudinal BFRP tension bar 21 bears the main tensile force across the crack, while the intersecting upper and lower BFRP tie bars bear the reinforcement and crack shear force. The BFRP grid 23 constrains the surrounding grout and increases the bonding range between the skeleton and the grout. The anchor bar 3 transfers the force at the end of the skeleton to the original wall. After the PVA-ECC grout hardens, it covers the skeleton and fills the repair groove 12 and the wall crack 11 connected to it, so that the original wall, the grouting body, and the BFRP composite reinforced skeleton 2 share the force, thereby achieving crack seepage prevention and sealing and structural reinforcement.

[0109] Example 2: The main difference between this second embodiment and the first embodiment lies in the construction control of the repair groove 12 and the anchor hole 13. The remaining skeleton, sealing and grouting steps can adopt the scheme of the first embodiment.

[0110] Repair groove 12 is a rectangular groove. First, regular boundaries are formed by cutting, then the concrete inside the groove is removed. After the groove is formed, it is roughened, then anchor holes 13 are drilled, and finally, the slag and dust generated during roughening and drilling are uniformly removed. This sequence avoids re-contamination of the cleaned groove surface after the anchor holes 13 are constructed.

[0111] For old concrete walls with high water absorption or relatively dry conditions, wetting can be done in two stages: after the first wetting, allow the wall to stand to allow moisture to penetrate the surface pores; after the second light wetting, continue to allow it to dry until no standing water remains. For walls already in a damp environment, do not add large amounts of water; simply remove any water that has accumulated in the trench and keep the trench walls moist. Regardless of the method used, there must be no flowing water or continuous water film on the trench walls before grouting.

[0112] This embodiment improves the interfacial bonding stability between PVA-ECC slurry and the original wall by controlling the interface roughness, cleanliness, and water content. It is suitable for repair projects where the surface of the old wall is significantly weathered and the water absorption rate varies greatly.

[0113] Example 3: In this embodiment, bidirectional basalt fiber mesh is used as BFRP grid 23, and a window corresponding to the injection port 41 is set on the grid.

[0114] The BFRP grid 23 can be constructed by wrapping the entire frame with mesh fabric and then overlapping and binding it, or by using multiple pieces of mesh fabric to cover the upper, lower, and side sides of the frame, and then overlapping and fixing them between adjacent mesh fabrics. Regardless of the method used, the longitudinal BFRP tension bars 21, the upper BFRP tie bars, and the lower BFRP tie bars should be within the coverage area of ​​the BFRP grid 23.

[0115] The distance between the BFRP grid 23 and the inner surface of the repair groove 12 can be maintained by non-metallic positioning pads, binding positioning elements, or tie bar end supports. The positioning elements should be compatible with the grout and should not form a continuous isolation surface between the skeleton and the groove wall.

[0116] The opening can be a rectangle of 75mm × 50mm, or other shapes can be used provided that the grouting pipe can pass through and the fiber grout can enter smoothly. The boundary of the opening should avoid the main stress connection points of the skeleton, and the size of the opening should not be larger than the reasonable range required to achieve grouting, so as not to excessively weaken the continuity of the grid coverage. This embodiment is particularly suitable for construction conditions using grout containing short fibers, grouting pipes with large diameters, or grid meshes with small openings.

[0117] Example 4: This embodiment uses a butyl rubber waterproof sealing tape 4 with a thickness of 5mm, a length of 700mm, and a width of 200mm. The length and width of the sealing tape 4 are greater than the groove size of the repair groove 12, so that there is a continuous adhesive area on each side of the groove.

[0118] When the original wall surface is relatively rough, first remove protruding particles and repair the area around the groove. Do not rely solely on increasing the thickness of the sealing tape to compensate for large holes. When applying the sealant, press it firmly from the center of the repair groove 12 outwards to expel air between the sealing tape 4 and the wall surface. The injection port 41 is set as a round hole with a diameter of 42mm, and the overflow port 42 is set as a square hole with a side length of 10mm.

[0119] In one parallel arrangement, the injection port 41 is located at the lower position of the repair trench 12, and the overflow port 42 is located at the higher position, allowing the grout to flow upwards and expel air. In another arrangement, the injection port 41 is located at one end of the repair trench 12, and the overflow port 42 is located at the other end away from the injection port 41, used to observe whether the grout has penetrated the main length of the trench. In both arrangements, the overflow port 42 should be aligned with a pre-designed overflow channel on the wall.

[0120] Example 5: In this embodiment, a miniature grouting pump and a DN32 grouting pipe are used to inject PVA-ECC grout. The example grouting flow rate is 5 L / min. A lower flow rate is used at the beginning of grouting to fill the space near the injection port 41 with grout and expel most of the air. After confirming that there is no obvious bulging or leakage at the edge of the sealing strip 4, the flow rate is gradually adjusted to the set flow rate.

[0121] Observe the overflow port 42 during grouting. If only air is discharged or grout drips intermittently, continue grouting; stop grouting when grout that is basically the same in appearance as the injected grout flows continuously and evenly from the overflow port 42, and there are no obvious air bubbles. Immediately seal the injection port 41 and the overflow port 42 after pulling out the grouting pipe.

[0122] After the grout has initially set, remove the sealing strip 4 and perform spray curing for no less than 7 days. For construction conditions with high ambient temperature, dry air, or high wind speed, shorten the spraying interval and increase the moisture coverage; for low-temperature environments, take insulation measures according to material requirements, and prevent the grout from freezing before it has formed a stable structure.

[0123] After curing, the wall surface is restored in layers using repair mortar. The first layer mainly fills the height difference between the surface of the grout and the original wall surface, and the second layer is used for leveling and finishing. Before each layer is applied, the surface of the previous layer is cleaned and the interface is treated according to the requirements of repair mortar to reduce sagging, hollowing, and shrinkage cracking caused by applying a thick layer at once.

[0124] Example 6: The process described in this embodiment is mainly applicable to concrete walls, especially to the repair and reinforcement of concrete retaining walls, underground concrete walls, and building concrete walls with deep or through cracks. It is not directly applicable to masonry walls. When using this process for grouting, the main objects of grouting are the repair groove and the space around the BFRP composite reinforcement skeleton. Under pressure, the grout can also partially enter the wall cracks connected to the repair groove, but the complete filling of all hairline micro-cracks far from the repair groove is not the acceptance target.

[0125] For cracks that extend or nearly extend along the wall thickness, inspect the crack openings and potential grout leakage channels on both sides of the wall before grouting. When construction can be carried out on both sides of the wall, while sealing the outer opening of the repair groove with butyl rubber waterproof sealing tape, continuously apply butyl rubber waterproof sealing tape along the corresponding area of ​​the crack on the other side of the wall to seal any channels through which grout may seep to the other side of the wall. The sealing tape on both sides should be continuously pressed together, without wrinkles, curled edges, or through gaps.

[0126] When repairing a concrete retaining wall whose back side is in contact with soil or other structures, check before grouting for any open areas, drainage holes, or other leakage channels on the back side of the wall that could lead to significant grout loss. If leakage channels exist, seal them first before proceeding with formal grouting. If, during grouting, continuous grout leakage is observed on the other side of the wall, the edge of the sealing strip curls up, or the grouting pressure becomes unstable, grouting should be stopped immediately and the pressure released. Construction can only continue after additional sealing is completed.

[0127] Grouting was performed using a miniature grouting pump capable of conveying fibrous slurry and a DN32 grouting pipe. Initially, a low flow rate was used to gradually fill the space near the grouting inlet and expel air from the cavity. After confirming that there was no significant bulging or leakage at the edge of the sealing strip, the grouting flow rate was gradually adjusted to approximately 5 L / min. The grouting pressure was controlled between 0.2 and 0.3 MPa.

[0128] As the grout is continuously injected, air inside the cavity is expelled through the overflow port. When the overflow port changes from venting or intermittent dripping to a continuous, uniform flow of grout that is essentially identical in appearance to the injected grout and free of obvious air bubbles, the main cavity between the injection port and the overflow port is considered to be essentially filled. Thereafter, a stable pressure of not less than 0.2 MPa is maintained for 3 minutes.

[0129] During the pressure stabilization process, observe the grouting pressure, grouting flow rate, grout overflow status, sealing strip deformation, and wall surface condition. If no continuous grout leakage, significant bulging of the sealing strip, groove cracking, or localized wall bulging occurs during the pressure stabilization period, stop grouting, slowly pull out the grouting pipe, and immediately seal the grouting port and overflow port. In construction conditions involving long grouting pipelines or where the grout needs to rise upwards, adjust the grouting pressure based on the on-site test results, but the adjusted pressure must not exceed the safe upper limit confirmed by the pressure-bearing tests of the wall substrate and sealing structure.

[0130] This embodiment uses ECC grout with a water-cement ratio of 20%, and adds PVA fibers with a volume fraction of 1.5% and a length of 8mm. This mix ratio is suitable for reinforcing cracks in concrete walls with a width of less than 3mm. Before formal grouting, the fluidity, uniformity, and pumpability of the grout are tested. It can only be used after confirming that there is no obvious segregation, fiber agglomeration, or pipe blockage.

[0131] For cracks with a width of not less than 3mm, the above-mentioned PVA fiber dosage should not be directly applied. Trial mixing and pumping tests should be conducted based on the crack width, repair trench volume, grouting pipe diameter, and pumping distance. The mix proportion should be determined under the condition that the grout can be pumped smoothly, the PVA fiber is uniformly dispersed, and the grout does not lose a large amount along the crack.

[0132] Test Example 1: Crack Resistance and Shear Resistance Test of Repaired Wall Concrete specimens measuring 1.2m × 0.5m × 0.45m were prepared, and each specimen had a pre-set vertical through crack with a width of 3mm. The through crack extended along the thickness of the specimen, with a vertical length of 0.3m. The experiment included a reinforced group using this process, a group reinforced with externally applied BFRP geogrid, and an unreinforced control group. Each group had [number of specimens specified].

[0133] The reinforcement process involves creating two repair grooves on the outer surface of the specimen on the tension side. The BFRP composite reinforcement skeleton described in this application is installed in each repair groove. Subsequently, PVA-ECC grout is injected according to the sealing and grouting process described in this application, and the specimen is cured to the specified age.

[0134] For the externally bonded BFRP geogrid reinforcement group, the outer surface of the specimen was first roughened, then a layer of PVA-ECC grout was applied, and the BFRP geogrid covering the outer surface of the specimen was placed and fixed. Finally, a 20mm thick layer of PVA-ECC grout was applied over the BFRP geogrid and cured to the specified age. The unreinforced control group did not receive any reinforcement measures.

[0135] Shear capacity tests were conducted on the three groups of specimens with a shear span ratio of 1.35. Concentrated loads were applied, with each load level being 20 kN. The initial cracking load, crack development state, mid-span deflection, ultimate load, and failure mode of the specimens were recorded.

[0136] Test Example 2: Pull-out Test of Anchor Bars Pull-out test specimens were fabricated using the same anchoring structure as in Example 1. The anchor bars were 10mm diameter HRB400 steel bars, with anchor holes of 14mm diameter and 120mm depth. The same epoxy resin adhesive used in the engineering construction was employed for anchoring, and the specimens were cured for the predetermined number of days before undergoing axial pull-out tests. Results were collected and compared based on the failure modes of the specimens.

[0137] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement, characterized in that, Includes the following steps: A repair groove is made on the outer surface of the wall, intersecting with the wall crack, and anchor holes are made on the inner wall of the repair groove. Assemble a BFRP composite reinforced skeleton, wherein the BFRP is basalt fiber reinforced plastic; the BFRP composite reinforced skeleton includes longitudinal BFRP tension bars, BFRP tie bars connected to the longitudinal BFRP tension bars, and a BFRP grid covering the longitudinal BFRP tension bars and the BFRP tie bars; both ends of the longitudinal BFRP tension bars are respectively connected to outwardly extending anchor bars; The BFRP composite reinforced skeleton is placed into the repair groove, and the anchor bar is anchored into the corresponding anchor hole; The outer opening of the repair groove is sealed with a sealing strip. The sealing strip is provided with an injection port and an overflow port that communicate with the repair groove. The sealing strip and the repair groove form a closed grouting cavity. Grout is injected into the sealed grouting cavity through the injection port, and the injection port and the overflow port are sealed after the injection is completed.

2. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, The method of creating a repair groove on the outer surface of the wall that intersects with the wall crack includes: A rectangular groove is made on the outer surface of the wall, intersecting with the wall crack. The inner wall of the groove is then roughened, scum and dust are removed, it is moistened with water, and then dried until there is no standing water. Anchor holes are made between the roughening and scum and dust removal processes. The anchor holes are made on the inner wall of the treated repair groove in a direction perpendicular to the wall surface.

3. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, Multiple longitudinal BFRP tension bars and multiple BFRP tie bars are provided, and the multiple longitudinal BFRP tension bars are arranged parallel to each other along the entire length of the repair groove. The BFRP tie bars include an upper BFRP tie bar located above the longitudinal BFRP tension bar and a lower BFRP tie bar located below the longitudinal BFRP tension bar. The upper BFRP tie bars and the lower BFRP tie bars are arranged at intervals along the longitudinal BFRP tension bar and are obliquely intersecting the longitudinal BFRP tension bar. The extension directions of the upper BFRP tie bars and the lower BFRP tie bars intersect each other.

4. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 3, characterized in that, Both ends of the longitudinal BFRP tension bar are covered with end BFRP fiber cloth, and the end BFRP fiber cloth is bonded to the longitudinal BFRP tension bar with epoxy resin adhesive.

5. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 3, characterized in that, The BFRP grid is a bidirectional basalt fiber mesh fabric; The BFRP grid is tied to the straight ends of the upper and lower BFRP tie bars, and covers the longitudinal BFRP tension bars, the upper BFRP tie bars, and the lower BFRP tie bars; after the BFRP composite reinforcement skeleton is placed into the repair groove, a gap is left between the BFRP grid and the inner surface of the repair groove.

6. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 5, characterized in that, The BFRP grid has a window between two adjacent horizontal bars, and the window is positioned opposite to the injection port on the sealing strip.

7. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, The anchor bar has a hook at one end facing the longitudinal BFRP tension bar, and the hook hooks the end of the longitudinal BFRP tension bar. The other end of the anchor bar is fixed in the anchor hole by anchoring adhesive.

8. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, The sealing strip is a butyl rubber waterproof sealing strip, which completely covers the outer opening of the repair groove; the injection port and the overflow port both penetrate the sealing strip, and the overflow port is set opposite to the overflow channel on the wall.

9. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, The slurry is a PVA-ECC slurry formed by mixing engineering cement-based composite material (ECC) with water and incorporating polyvinyl alcohol (PVA) fibers.

10. The wall crack grooving and grouting reinforcement and repair process based on BFRP composite reinforcement as described in claim 1, characterized in that, Grout is injected into the sealed grouting cavity through the injection port, and the injection port and the overflow port are sealed after the injection is completed, including: The grout is injected using a grouting pump and a grouting pipe; after the grout flows out of the overflow port continuously and evenly, the grouting pipe is pulled out and the injection port and the overflow port are sealed. The wall crack grooving reinforcement and repair process based on BFRP composite reinforcement also includes: removing the sealing strip after the grout has initially set, spraying the formed grout body for curing, and then using repair mortar to smooth the outer surface of the wall corresponding to the repair groove in layers after curing.

Images